Question

What is the value of the expression 1/2-(-1/3 + 2/5)?

Answer 1

Answer:

13/30

Step-by-step explanation:

Add: -1/

3

+ 2/

5

= -1 · 5/

3 · 5

+ 2 · 3/

5 · 3

= -5/

15

+ 6/

15

= -5 + 6/

15

= 1/

15

For adding, subtracting, and comparing fractions, it is suitable to adjust both fractions to a common (equal, identical) denominator. The common denominator you can calculate as the least common multiple of the both denominators - LCM(3, 5) = 15. In practice, it is enough to find the common denominator (not necessarily the lowest) by multiplying the denominators: 3 × 5 = 15. In the next intermediate step the fraction result cannot be further simplified by canceling.

In words - minus one third plus two fifths = one fifteenth.

Subtract: 1/

2

- the result of step No. 1 = 1/

2

- 1/

15

= 1 · 15/

2 · 15

- 1 · 2/

15 · 2

= 15/

30

- 2/

30

= 15 - 2/

30

= 13/

30

For adding, subtracting, and comparing fractions, it is suitable to adjust both fractions to a common (equal, identical) denominator. The common denominator you can calculate as the least common multiple of the both denominators - LCM(2, 15) = 30. In practice, it is enough to find the common denominator (not necessarily the lowest) by multiplying the denominators: 2 × 15 = 30. In the next intermediate step the fraction result cannot be further simplified by canceling.

In words - one half minus one fifteenth = thirteen thirtieths.